Many angry 50s women frustrated they can’t get a pension for up to six years – have the power at the ballot box to knock out the MPs who voted for the change. Since the next general election will be closely fought and many seats have narrow majorities they are literally – no pun intended -in poll position to effect change.

There isn’t a constituency in the United Kingdom that has less than 3000 of these pensioners according to a breakdown helpfully provided by the House of Commons library.

And it is the current Theresa May government and her DUP allies who are vigorously pursuing higher and higher retirement ages for future generations of pensioners that are the MPs most at risk. The Conservatives got a high proportion of votes from the over 60s at the last general election so need these votes to win the next election.

The biggest voter power of this group is in the Isle of Wight – where there are over 10,000 people affected by the raising of the pension age.The Tory MP, Bob Seely appears to have an impregnable 20,998 majority – but that would be halved if this group of people voted didn’t vote for him.. The main challenger there is Labour who came second and if people switched their vote to Labour it would become a highly marginal seat.

Much more vulnerable is home secretary and ironically women and equalities minister Amber Rudd, whose Hastings and Rye seat, has 7400 people affected. She has a majority of 366 and Labour is the main challenger. There are 20 times more people hit by the change than her majority.

Another ultra marginal is Calder Valley where the Conservative MP Craig Whittaker,a Treasury whip, has a majority of 609 over Labour. There are 7000 people affected by the change in his constituency.

Similarly Corby where Tom Pursglove has a Conservative majority of 2,690 – it is more than outnumbered by 7,300 people affected. Both Milton Keynes seats (North and South) have small 2000+ Tory majorities but over 14,000 people affected between them. And Scarborough where Conservative MP Robert Goodwill has a 3435 majority is dwarfed by 7,100 people affected.

The entire London borough of Barnet is another hotspot. Chipping Barnet, where Theresa Villiers, Conservative MP and ex minister, has a 353 majority has 6,200 people affected. Labour is again the main challenger. Next door Hendon which also has 6.200 people affected. Tory MP Matthew Offord has a majority of 1072 over Labour .In Finchley and Golders Green Tory Mike Freer has a majority of 1657 over Labour and there are 6000 people affected.

There are also a string of safe Tory seats with between 7,000 and 7,800 pensioners who have lost out where the Tory majority can be severely dented or turned into marginals by switching to the highest challenger. Among these are Beverley and Holderness ( Graham Stuart majority 14,042); Bridgewater and West Somerset ( Ian Liddell-Grainger majority 15,448); Croydon South ( Chris Philp majority 11,406); South Dorset ( Richard Drax majority 11,695), Wells (James Heappey, majority 7585 over liberal democrat) and Berwickshire, Roxburgh and Selkirk ( John Lamont, majority 11,060).

Among Labour seats with over 7,000 pensioners affected include marginal Colne Valley (Thelma Walker majority 915) and safe seats Croydon North and Brent North. The most marginal with over 7000 affected people is Rutherglen and Hamilton West held by Gerrard Killen with a majority of 265 over SNP.

DUP seats with the largest numbers of people affected ( 6500 and 6400 respectively) are Upper Bann held by David Simpson with a 7,992 majority and Antrim North held by Ian Paisley Jnr with a 11,546 majority.

None of the Welsh Parliamentary seats had more than 7000 pensioners.

In addition there are those with lower numbers of people affected but who could influence the result. One is East Worthing and Shoreham which has 6,100 people affected. The MP is chair of the All-Party Parliamentary Group on State Pension Inequality for Women pensioners group, Tim Loughton. He has a 5106 majority over Labour.

These results suggest that Waspi and BackTo60 supporters supporters have more influence than they realise. It is a question of energising it.

Check your own constituency in the table here.It is an Excel document. Go the page and scroll until the bottom and click on constituency estimates.